Acoustooptic attenuation filters based on tapered optical fibers

This paper studies the acoustooptic interaction induced by an acoustic flexural wave among the optical propagation modes supported by tapered optical fibers. We have investigated the evolution of the acoustooptic resonance condition as the fiber is progressively tapered, showing that the taper radius can be regarded as a new degree of freedom in the design of acoustooptic filters. Finally, we demonstrate a novel acoustooptic filter based on nonuniform tapers for dynamic gain flattening of optical fiber amplifiers.